Disazo dye.



NrTEn STATES PAUL JULIUS, OF LUDIVIGSHAFEN, GERMANY, ASSIGNOR TOBADISOHE ANILIN & SODA FABRIK, OF SAME PLACE.

DISAZO DYE.

SPECIFICATION formingpart of Letters Patent No. 677,230, dated June 25,1901. Application filed February 25, 1901. Serial No. 48,783. (Nospecimens.)

To an whom it may concern.-

Be it known that I, PAUL JULIUS, doctor of philosophy and chemist, asubject of the Emperor of Austria-Hungary, residing atLudwigshafen-on-the-Rhine, in the Kingdom of Bavaria and Empire ofGermany, have invented new and useful Improvements in Disazo Dyes, ofwhich the following is a specification.

If the nitro-amido-phenol-sulfo acid to which the constitution f vo, l/NH so? is attributedthat is, the para sulfo-acid ofortho-nitro-ortho-amido-phenol (see Letters Patent granted to me, No.644,234, dated 27th of February, 1900)-be reduced, the correspondingdiamido-phenol-sulfo-acid is obtained. Upon diazotizing thisdiamido-phenol-sulfo-acid atetrazo compound results, and I havediscovered that this tetrazo compound upon combination first with one ofthe components hereinafter set forth and then with a second of suchcomponents new mixed or unsym metrical disazo coloring-matters areobtained, possessing excellent qualities. The said components arebeta-naphthol, 2. 6 beta-naphtholmonosulfo-acid,andbeta-hydroxy-naphthoic acid of meltingpoint 216 centigrade, and thelike. The coloring-matters so obtained dye wool from the acid-bath,giving shades which vary from bluish violet to greenish blue, and upontreating the dyed goods with potassium bichroniate violet shades becomebluer and greenish shades become greener, while all become more intenseand assume a great fastness against the action of milling, washing, andlight. Further, the shades so obtained do not suffer when the goods aresteamed or carbonized.

In the present application I do not desire to claim mynew mixed disazocoloring-matter that can be obtained as above defined generically, forthe said coloring-matter is generically claimed in a separateapplication for Letters Patent, Serial No. 48,335, filed February 21,1901; but what I wish to claim in this application is the specific mixeddisazo coloring matter which can be obtained from one molecularproportion each of beta-hydroxynaphthoic acid of melting point 216centigrade and beta-naphthol.

Although I do not claim the process for the production of thediamido-phenol-sulfo acid, I give the following example of a method bywhich it maybe obtained for the sake of clearness, the parts being byweight:

Example 1: Dissolve about four hundred and sixty-eight (468) parts ofortho-nitro-orthoamido-phenol-para-sulfo-acid in two thousand (2,000)parts of hot water. Stir the solution and slowly add about seven hundredand fifty (750) parts of zinc-dust, and subsequently, in small portionsat a time, about two thousand (2,000) parts of-hydrochloric acid,(con'-taining about thirty-two per cent. of real H01.) Allow the solution tocool, collect the precipitate, and redissolve it in hydrochloric acid.Filter the solution and neutralize it exactly with carbonate of soda.The desired diamido-phenol-sulfo-acid separates out as free acid in theform of a slightly yellowish crystalline precipitate. Collect byfiltering, wash with cold Water, and dry carefully.

The following example will serve to illustrate the manner in which myinvention may be carried into practical effect and new coloring'matterobtained, the parts being by weight:

Example 2: Prepare a solution of about two hundred and four (204) partsof the diamido-phenol-para-sulfo-acid, obtained as described in theforegoing example, in three thousand (3,000) parts of water containingfour hundred and sixty (460) parts of hydrochloric acid, (containingthirty-two per cent. of H01.) To this solution when cold add graduallyone hundred and thirty-eight (138) parts .of sodium nitrite dissolved infour hundred (400) parts of water. The tetrazo compound is soon formedand partially separates out. Run the solution or suspension of thetetrazo compound thus obtained into a solution of one hundred andforty-four (144) parts of beta-naphthol and forty (40) parts of solidcaustic soda in fifteen hundred (1,500) parts of water. Stir the mixedsolutions until combination is complete, which is the case in a shorttime. The intermediate product obtained separates out as a redprecipitate. Filter it oif, stir it up into a paste with water, and runit into a solution of two hundred and ten (210) parts ofbeta-hydroxy-naphthoic acid (which has a melting-point of 216 centigrade) and two hundred (200) parts of carbonate of soda in four thousandfive hundred (4,500) parts of water. \Varm the solution to a temperatureof sixty (60) degrees centigrade and stir until combination is complete.The new coloring-matter separates out. Filter it off, press, and dry.

My new coloring-matter thus obtained is soluble in water, giving a bluesolution which when very dilute is violet-red. Upon the addition ofcaustic soda to the blue solution a dark-blue precipitate is formed. Ithydrochloric acid be added to the blue aqueous solution, a redprecipitate is formed, and the solution of the coloring-matter inconcentrated sulfuric acid is violet. The coloringmatter can readily bereduced, for instance, with stannous chlorid in hydrochloric-acidsolution, With zinc-dust and ammonia, or with other suitable reducingagents. hen suitably reduced, three reduction productsnamely, theabove-mention ed diainido-phenolsulfo-acid, amido beta hydroxy naphthoicacid, and amido-naphtholare produced and can be recognized.

Now what I claim is- The new disazo coloring-matter which can beobtained from diamido-phenol-sulfo-acid, beta-naphthol andbeta-hydroXy-naphthoic acid which is soluble in water giving a bluesolution which when very dilute is violet-red,

in which blue solution a dark-blue precipitate is formed by the additionof caustic soda, and a red precipitate by the addition of hydrochloricacid and which dissolves in concentrated sulfuric acid the solutionbeing violet, and which upon suitable reduction yields diamidophenolsulfo acid, amido-beta-hydroxy-naphthoic acid, andaniido-naphthol, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

PAUL JULIUS.

Witnesses: I

PAUL SEIDEL, JOHN L. Hnmnn.

